Mobile subsurface mine-field.



S. l. PRESCOTT. MOBILE SUBSURFACE MINE FVIELD.

APPLICATION FILED JUNE 13. 1917.

1,287,744. I Patented Dec; 17, 1918.

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SYDNEY I. PRESCOTT,

OF NEW YORK, N. Y.

MOBILE SUBSURFACE MINE-FIELD.

Specification of Letters Patent.

Patented Dec. 17, 1918.

Application filed June 13, 1917. Serial No. 174,447.

To all whom it may concern:

Be it known that I, SYDNEY I. Pnnsco'r'r, a citizen of the United States, residing at New York, county of New York, and State of New York, have invented a new and useful Improvement in Mobile Subsurface Mine-Fields, of which the following is a specification. it

This invention relates to a mobile subsurface mine field, and it has for its main object the production of a mine field which may be moved into and out of and while in action, and from one station to another, unobserved by an enemy. A further object is the production of amine field of the gen eral character above indicated which may at any time be brought to the surface of the water for inspect-ion and repairs. Another object is the production of a mine field which will retain its mobility after one or more of its mines have been exploded. Still another object is the production of the simplest possible structure by means of which the desired objects may be attained. lVith these and other objects not specifically mentioned in view, the invention consists in certain combinations and constructions which will be hereinafter fully described and then specifically set forth in the claims hereunto appended.

In the accompanying drawings, which form a part of this specification and in which like characters of reference indicate the same or like parts, Figure 1 is a diagrammatic view showing a device constructed in accordance with the invention in the position it will occupy when not in service; and Fig. 2 shows the same structure in the position it occupies when in service.

In carrying the invention into effect, there is provided a series of mines having buoyancy enough to float awash when not in service, and means in itself submergible connected with and for submerging said mines to a predetermined level and for moving them at that level. In the best constructions, a pair of submarines connected with and cooperative for sub-merging the mines is employed. In the best constructions also, means are employed for connecting the mines and for spacing them apart in a single line. In the best constructions also, means are employed for maintaining intercommunication between the two submarines to facilitate their cooperation. All of these meansniay be varied in construction within wlde llmits.

The device selected to illustrate the in-" vention is but one of many possible concrete embodiments of the same. The invention, therefore, is not to be restricted to the precise details of the structure shown and described.

Referring to the drawings: 3 indicates a wire hawser which of course is non-buoyant. Rising from this hawser is a series of rope verticals 4, and at the upper end of each vertical is a mine 5. The mines 5 have buoyancy enough to support the hawser 3 and the verticals 4, and to cause the mines 5 to fioat awash when the structure is not in service. hen the mines are floating awash, they may be readily inspected; and repairs may be made without withdrawing the structure from its station.

Any type of mine suitable for the pur poses intended may be employed. The mines are spaced apart in a singl line, near enough together to prevent the passage of a ship without contact, but not near enough for mine fouling. They may be painted for invisibility even from the air, when submerged.

The verticals 4 are long. This is for two reasons; first, to support the hawser 3 at a distance from the mines great enough to prevent mine explosion from parting the hawser; and second, to bring the hawser, when the structure is submerged, low enough to avoid fouling the keel of a ship running into the field. A convenient vertical length is approximately thirty feet so that when the mines are submerged to a depth or level of ten feet, the hawser will lie forty feet below the surface of the water, low enough to clear any ships keel. A ship may pass over the hawser and explode a mine without otherwise disturbing the field, and Without disturbing its alinement at all.

As before stated, the buoyancy of the mines is just suflicient to float the structure as a whole with the mines awash when it is not in service. Consequently, little force is required to overcome this buoyancy, and for this purpose, and for the further purpose of concealing the movement and opera tion of the field from an enemy, two submarines, not shown but indicated by the characters L. S. and R. S., are used, one

connected with each end of the hawser 3.

It is well known'that submarines are provided with means whereby they may submerge to a predetermined depth or level and move at that level. This attribute of submarines is here utilized for the purpose of submerging the whole structure to a predetermined level and for moving it at that level. It may be here remarked that the length of the hawser and the number of mines carried by it will depend upon the power of the submarines used, or upon the sea room where it may be in service. It may be made up of units coupled together. When the structure goes into action as a whole, the leading submarine L. S. submerges to-the predetermined level and operates its motors to move ahead. The rear submarine R. S. submerges to the same level but stops its motors. The pull of the leading submarine upon the hawser 3 straightens the same down to its proper level,'the rear submarine acting as a drag or submerged sea anchor. The straightening of the hawser at its proper level results in pulling the mines down to their proper level. When all parts of the structure are at their respective levels, the field is inoperative position and. is entirely concealed. from an enemy. It may then be towed inconcealment to any desired station at full speed of a submerged submarine towing another, without fouling the mines spaced with this end in view. In fact, the rear' submarine may aid by turning its motors over at a speed less than that of the motors of its leader.

. "When operating on station, the leading submarine keeps its motors turning over just fast enough to fully maintainsteerage way. Under these conditions, the drag of the rear submarine will keep the mines in their proper position. If for any reason it is desired to temporarily hold the field stationary, the rear submarine reverses its motors to counteract the towing action of its leader. A backing and filling operation may easily'be effected. The field may be turned like any other long tow. Having due regard for drift, tidal or other currents, the field may thus be maintained in operation wherever there is water enough. It

may be here remarked that Wherever a battleship can maneuver, there this mine field is operative.

When the mine field is in operative position, and whether it be moving slowly or held stationary, a ship crossing the field will strike one of the mines, possibly two, and if they are contact mines will automatically cause an explosion. It will be remembered that. the'hawser is maintained at a level below the keel of the largest ships. When a ship is mined, therefore, its momentum will carry it on overthe hawser, and'if the field is moving, as it should be'wherever there is room for movement, the ship will be struck a second tlme and farther aft by a mine adjacent the one first exploded. The

second explosion will usually occur on the same side as the first, with the probable result that the ship will turn turtle.

Of course, after one or two mines have been thus exploded, there will be a break in the mine field. There will, however, be no surface indication to an enemy where this break is, for if the field is moving the break will not be where the first explosion occurred by the time another ship in line arrives at that point. 'If no other enemy is in sight, the submarines may emerge and permit the mines to rise to the surface. A tender may then repair the damage to the mine field,

after which the whole structure may be again submerged. To dismantle the field,

the mine tender first picks up the mines, and

then the hawser with its verticals.

This mobile mine field may be used, not only for blockade purposes in estuaries and channels, but also in battle in deep water; and when so used, independent mobile mine fields may be readily employed for cutting of advance. or retreat'of enemy ships in. battle line, without in any way interfering with ones own battle line. Other uses to I which it may be put in both major and minor operations which need not be mentioned here will suggest themselves to those familiar with the subject.

For the purpose of intercommmlication between the two submarines to facilitate cooperative action, there may "be employed a light submarine cable, not shown, but of a well known character, triced up to the hawser .8. The particular construction of this means of intercommunication lies wholly outside of the present invention and a descrip tion and illustration thereof is therefore omitted in the interest of brevity and clear ness. i

What is claimed is: V

1. A mobile sub-surface mine fieldcomprising a series of connected mines having buoyancy enough to float awash when not in service and support the connections between said mines, and means in itself submergible connected with and for. submerging said mines to a pie-determined level and for moving them at that level.

2. A mobile subsurface mine field comprising a series of connected mines having buoyancy enough tofioat awash when not in service and support the connections between said mines, means for connecting said mines and spacing them apart in a single line, and means initself submergible connected with said spacing means for submerging said mines to a predetermined level and for meving them at. that level.

3.'A mobile sub-surface minefield comprising a series of connected mines having buoyancy enough to float awash when not in service and support the connections between said mines, a hawser below the mines, verticals connecting the mines with the hawser, and means in itself submergible connected with said hawser for submerging said mines to a predetermined level and the hawser to a lower level and for moving them at said levels.

4. A mobile sub-surface mine field comprising a series of connected mines having buoyancy enough to float awash when not in service and support "the connections be tween said mines, a hawser far enough below the mines to escape injury from mine explosion, verticals connecting the mines with the hawser, and means in itself submergible connected with said hawser for submerging said mines to a pre-determined level and the hawser to a level low enough to avoid fouling a ships keel and for moving said mines and said hawser at said levers.

5. A mobile sub-surface mine field comprising a series of connected mines having buoyancy enough to float awash when not in service and support the connections between said mines, a wire hawser below the mines, rope verticals connecting the mines with said hawser, and a pair of submarines one connected with each end of said hawser and cooperative for submerging the whole structure to a pre-determined level and for moving it at that level.

6. A mobile sub-surface mine field comprising a series of connected mines having buoyancy enough to float awash when not in service and support the connections between said mines and a pair of submarines connected with said mines and cooperative for submerging them to a predetermined level and for moving them at that level.

7. A mobile sub-surface mine field comprising av series of connected mines having buoyancy enough to float awash when not in service and support the connections between said mines, a hawser below the mines, independently movable verticals of equal length connecting the mines with the hawser, and means in itself submergible connected with said hawser for submerging said mines to a predetermined level and the hawser to a lower level .and for moving them'at said levels.

8. A mobile sub-surface mine field com prising a series of connected mines having buoyancy enough to float awash when not in service and support the connections between said mines, a hawser far enough below the mines to escape injury from mine explosion, independently movable verticals of equal length connecting the mines with the hawser, and means in itself submergible connected with said hawser for submerging said mines to a predetermined level and the hawser to a level low enough to avoid fouling a ships keel and for moving said mines and said hawser at said levels.

9. A sub-surface mine field comprising a series of connected mines having buoyancy enough to float awash when not in service and support the connections between said mines, and means connected therewith for submerging said mines to a predetermined level.

In testimony whereof, I have signed my name to this specification.

' SYDNEY I. PRESCOTT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

